Subject: AUTOMOTIVE FLUID POWER SYSTEMS (A.A. 2021/2022)
Unit Automotive Fluid Power Systems
Mechanical Engineering (lesson)
-to achieve basic knowledge of the main fluid power systems on board a light and heavy vehicle
-to achieve the ability to understand the characteristics and operation of a fluid power system
-to achieve basic knowledge on the lumped parameters approach in the modelling and dynamic analysis of fluid power systems
Previous knowledge on the dynamic behaviour of vehicles, on the fluid power systems and components and on numerical modelling using systems of differential equations are appreciated and make easier the course understanding BUT they are not mandatory
- Fluid power basic notions (graphic symbols, components, basic systems)
-Fluid power systems for light and heavy vehicles: description, operation, critical features of suspension system, braking, steering. Hydrostatic transmission will be also briefly considered
-Modelling and simulation of fluid power system and components
-Lumped parameters approach for the dynamic analysis of the fluid power systems previously described
-lectures -in-class exercises -homework
Evaluation Methods: Homework + Oral exam; a week before the exam date the student should send a report of the homework, described in the following: 1.Exercises developed in Excel and VBA for Excel, given during the course 2.Written report about the modelling and simulation of a hydraulic system, with the lumped parameter approach. The kind of system modelled should be proposed and discussed with the teacher during the course or when the student decides to prepare the exam (via appointment with the teacher required by the student with an email). During the course the teacher will propose some examples from the previous years. The report should contain: the description of the system and of the aims of the simulation, the design of the characteristic parameters of the system, the description of the model and simplifications introduced, the discussion of the main results. This part of the homework may be developed by one single student or by a group of maximum three persons. In this last case, the students of the same group may give the exam in different dates, in any case they should send the report one week before the date chosen to give the exam. The oral exam is constituted by three questions: 2 questions regard the main theoretical topics studied during the course, the third question regards the report and/or exercises. The answers may require to write on paper (draw a hydraulic diagram, write equations and relations..) but will be in any case discussed and described verbally with the teacher. Duration of the oral exam: about 40 minutes; there will not be intermediate tests during the course. Exam’s evaluation: A grade is assigned to each answer and the final grade is an arithmetical average of the three. The grade of the third question regarding the report and/or exercises will be an evaluation of the homework itself plus the ability of the student to explain the logical process behind the work and his/her knowledge about the simulation tools used to develop the model. Use of books or other tools during the exam: It is not allowed to use any auxiliary tool during the exam, a part from the report or exercises when the teacher will ask something about them.
- basic knowledge of the main fluid power systems on board a light and heavy vehicle
-capacity to understand the characteristics and operation of a fluid power system
- basic knowledge on the lumped parameters approach in the modelling of and dynamic analysis of fluid power systems
-M.J., Nunney, Light and Heavy Vehicle Technology, Butterworth-Heinemann, Elsevier.
-N. Manring, Hydraulic Control Systems, John Wiley & Sons, Inc. New York.
-Nervegna, N. Oleodinamica e Pneumatica, POLITEKO